TROUBLE CODES

My check engine lit up. I used to average over 28 mpg. Now, it's 20 mpg. I went to AutoZone, used their OBD scanner and got these codes. (P0171 Bank 1 system too lean), P0125 (Closed loop fuel sontrol insufficient coolant temperature, P1130 and P1135 ( Manufacturer control fuel air metering).
What can I do to fix this.
Thank you very much,
Emmanuel Carpio

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires